Brake-shoe.



C. D. PETTIS & P. H. BATTEN.

- BRAKE SHOE. APPLICATION FILED'DEO. 10, 1909.

Patented July 28, 1914,

3 SHEETS-SHEET 1 liwalihnfl 44 2. m 3& finfi a G. I). PETTIS & P. H.BATTEN BRAKE SHOE. APPLICATION FILED DEO.10, 1909.

Patented July 28, 1914.

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UNITED STATES PATENT OFFICE.

CLIFTON I). PE'ITIS AND PERCY H. BATTEN, OF CHICAGO, ILLINOIS,ASSIGNOBS, BY MESNE ASSIGNMENTS, T0 AMERICAN BRAKE SHOE &FOUNDRY-COMPANY, A COBr- I'ORATION OF NEW JERSEY.

BRAKE-SHOE.

Specification of Letters Patent.

Patented July 28, 1914.

to that class of brake shoes in which the cast metal body of the shoe isreinforced by a' back of soft steel or like ductile metal, and theobjects of the invention are, first, to provide a more effective andstronger back for the shoe.

An example of the type of brake shoe to which our invention relates isshown in Letters Patent No. 924,930, granted. to the National Brake ShoeCompany, as assignee of Clifton D. Pettis, June 15, 1909.

The invention consists in the features of improvement hereinafterdescribed, illustrated in the accompanying drawings and particularlypointed out in the claims at the end of this specification.

Figure 1 is a plan view' showing how the sheet metal backs are formedfrom a continuous strip. Fig. 2 is a plan viewupon a larger scale thanFig. 1, showin how the initial bending of the back plate 1s effected.Fig. 3 is a view in side elevation of the partiall formed back plateillustrated in Fig. 2. Fig. 4 is a plan view showing the comleted backplateembodying our invention.

ig. 5 is a view in side elevation of the back plate. Fig. 6 is a view invertical transverse section on line 66 of Fig. 8, and Fig. 7 is a viewin cross section on line 7-7 of Fig. 9, these sections showing also thecast metal body of the shoe united to the ductile.

metal back. Fig. 8 is a plan view of the shoe complete. Fig. 9 is aview'in longitudinal section on line 99 of Fig. 8. Fig. 10 is .a view intransverse section on line 1010 of Fig. 8.

The body 12 of the shoe may be formed of cast iron of suitable qualityand sha e, and the reinforcin back may be of so t steel or other ductilemetal. The invention is shown as a plied to a brake shoe moreespeciallydesigned for the driving wheels of locomotivesythat is to say, the shoehas a braking-face 14 adapted to bear upon the tread of the wheel, and agroove 15 adapted to receive the flange of the wheel. The reinforcingback 16 extends nearly from side to side and approximately from end toend of the body of the shoe at-its back. Preferably, the curved portionof the back 16, which extends over the flange engaging portion of theshoe body, is provided-with a series of openings 17 to permit the castmetal shoe body to more efi'ectively engage and in- I terlock with thereinforcing back. In the back 16 of the shoe there is formed alongitudinal opening 18, opposite one end of which a hole will be formedin the body of the shoe to receive the usual retaining bolt thatcooperates in connecting the brake shoe to the brake head. At one end ofthe shoe there is formed an attaching lug 22 that is integral with theback 16, this lug being bent upwardly and ba-ckwardly, as shown in thedrawings, and being formed with a central arch or corrugation 23, inorder to give increased strength thereto. 7

The end portion of the back 16 of the shoe is formed with a longitudinaldepression or corrugation 24 that corresponds and unites with thecorrugation '23 of the lug 22. Preferably, this depression orcorrugation 24 at the end of the back 16 has its forward end taperingand terminates at a pointat or near one end of the slot 18. The purposeof the depression or corrugation 24 is two-fold, viz: to give increasedstrength to the end portion of the shoe, and to avoid any sharp cuttingedge that, might tend to cut away the tread surface of the wheel, as thebody of the shoe is worn down.

It will be understood that the back 16 of the shoe will be set in. themold and the metal body of the shoe will be cast thereon in manner wellunderstood by those familiar with the manufacture of this t pe of brakeshoe. The cast metal will dw into the openings 17 and 18 of the back 16and around the base of the lug 22. In practice it will be found that, asthe cast metal body of the "shoe reaches the extreme of its wear, thelongitudinal corru ation 24, ta ering inwardly, as it does, will afiordno s arp cutting edge that might tend to groove or-mar the tread surfaceof the wheel. The corruga tion formed centrally of the lug 22 will vgive great rigidity to this lug and, being located in line with thecorrugation 24: in the back 16 of the shoe, the two corrugations can beformed at one and thesame operation. The feature of forming an attachinglug with a corrugation that extends beyond the base of the lug and for adistance into the body of the back plate is an important one, since itstrengthens the lug-particularly at its base, where it is subject toexcessive strain and where therewould be danger of breakage, if thecorrugation terminated at such point.

By reference more particularly to Fig. 10 of the drawings, it will beseen that the hole 19 in the back plate, at the end of the slot formedof 18, is larger than the hole 13 formed in the cast metal body 12 ofthe shoe to admit the usual attaching bolt whereby the shoe is connected to the brake head, and it will be noticed that a shoulder orliner of cast metal is thus interposed between the attaching bolt andthe edge of thehole 19. One advantage in thus forming the hole 19materially larger than the hole 13 is that the contact of the attachingbolt with the edge of the back 16 is avoided and the danger of cuttingthe bolt is correspondingly lessened.

By reference more particularly to Figs. 4, 5 and 6 of the drawings, itwill be seen that the back plate 16 has one of its ends formed with abroad notch 25 and a narrow notch 26, and at its opposite end, adjacentthe hook 23, the back plate is formed with a notch 27.

The notch 25 corresponds in width and shape Y with the end portion ofthe lug 22. By forming the broad notch 25, and, preferably also, thenarrow notch 26, in one end of the shoe, the cast metal end lug 28 maybe ater strength than would be possible if t e end of the back plate 16were not notched, but extended unnotched beneath the end lug 28.

In forming the back of the shoe (see Figs. 1, 2 and 3)"a strip of metalof suitable width and thickness is first placed beneath a set of diescomprising dies 30 adapted to form the several holes 17, a die 31adapted to form the long slot 18 and its end hole 19, a die 32 adaptedto form the notch 26 at one end of the plate, and dies 33 and 34 adaptedto cut away the metal between the adjacent back plates and at" the sidesof the attaching lug 22. At the same time that these several diesperform their operation, a knife simultaneously operates to sever thetongue or lug 22 from that part of the metal strip that is to' ing thusbeen made in flat shape, is next placed within a suitable die that givesto the plate the corrugation that comes opposite the flanged portion ofthe finished shoe and givesto the plate and its lug 22 the corrugations24 and 23, respectively. By the operation of these dies the lug 22 isleft at an angle of about 45 to the back plate, so that it maybe readilyoperated on by the next succeeding set of dies, which completes thebending of the lug 22 to the shape shown in Figs. 4 and 5 of thedrawings.

Having thus described our invention, what we claim as new, and desire tosecure by Letters Patent, is

1. A reinforcing back for brake shoes, comprising a plate of tough metalhaving at one end a corrugation extending inwardly toward the face ofthe shoe and tapering toward the center of the shoe.

2. A reinforcing back for brake shoes, having at one end an attachinglug provided with a corrugation and having the end portion of the backprovided with a corrugation corresponding to that of the lug and joiningtherewith.

3. A reinforcing back for brake shoes, comprising a plate of tough metalhaving at one end an attaching lug formed integral therewith, said lugand the end portion of said back being provided with joinedcorrugations, -the inner end of the corrugation 1n the back beingtapered.

\ 4. A brake shoe comprising a cast metal body and a reinforcing backplate of ductile metal, both of said parts having 'holes formedtherethrough to receive an attaching bolt, the hole of the back platebeing larger than the hole of the cast metal body, whereby a liner ofcast metal is formed within the hole of the back plate.

CLIFTON D. PETTIS. PERCY H. BATTEN.

